Suzuki 2 Strokes

My Ts185 runs hot and it has a flat spot in the upper rpms after first gear . It runs good in the lower rpms and idles nice as well. What could be the causes of this problem?

It's honestly impossible to diagnose or re-jet a two stroke over the internet- too many variables (your altitude, climate, fuel used, plug reading, motor's existing condition, leaks, air filter changes, ignition, and we obviously can't smell or hear it run for clues).

I'll give it a shot!

To me, the flat spot on top and running hot points to a plugged or lean carb. You haven't given enough info to really go much further, we'd need to know what you've checked and done already. Does flipping the choke on make it run temporarily better or worse?

First thing- old fuel. Have you disassembled and cleaned the carb, gas tank, petcock? Start there, new plug and clean air filter and you're probably there.

Does it run flat at higher RPMs or at high throttle opening? If you are unsure, get the bike in 2nd or 3rd and run up to redline at half throttle, Do you still have the problems? If it fine then that way, the flat spot is caused by the carb as suggested by Sandman. If you do have the same issue at 1/2 throttle or any throttle position I would be looking at the ignition for problems. Could be too far advanced if its getting hot.